The MDN uses the name of these attributes too describe them, so it doesn't really explain them. They dont really seem to have a default functionality to them, so I'm assuming min and max needs to be used with them. Does the browser use them somehow, or is their sole purpose to be used with javascript? Also is it possible to style the meter's other then width and height?
<meter min="0" low="30" value="50" optimum="50" high="80" max="100" >
What is their use?
</meter>